Pump



Dec. 16, 1952 F, E CARLSON 2,621,606

PUMP

Filed May 12, 1950 2 SHEETS-SHEET l j] j 5 ya 15a z farfzgys PatentedDec. 16, 1952 PUMP Floyd E. Carlson, Rockford, Ill., assigner toSundstrand Machine Tool C0., a corporation of Illinois Application May12, 1950, Serial No. 161,539

7 claims. 1

This invention relates to a pump, and more particularly to a pump havingimproved means for providing a seal between the inlet and outlet portsthereof.

The general object of this invention is to provide an improved pump.

Another object of this invention is to provide a pump having anon-rotatably mounted cylinder block which is bodily movable in a`generally circular path within a cylindrical chamber with an end Ywallhaving inlet and outlet openings, said block vhaving an end faceengaging said end vwall and at least one cylinder port opening into saidend face, and means for exerting variable pressure to force the end faceof the block against the end'wall of the chamber.

Another object is to provide a pump of this character in which saidvariable pressure increases as the speed of movement of the blockincreases.

Another object is to provide a pump of this character in which the meansfor `exerting variable pressure comprise a'flyball governor device onthe drive shaft of the pump and a thrust bearing between the governorand the cylinder block, said governor having a cam surface engaging afollower to increase the pressure of said bearing as the speed ofrotation vof the drive shaft increases.

vAnother object is to provide a pump in which the drive means maybestarted and brought upto substantially full speed before the full loadis applied to reduce torque during ystarting and acceleration of the`drive means and in which the load is removed as ythe drive meansdecelerates.

Another object is to provide a pump of this character in which the meansfor exerting variable pressure comprise a spider secured to the driveshaft, a `pair of weights pivotally mounted on the spider and movableaway from the drive shaft as a function of the speed of rotation of saidshaft, and a lthrust bearing between the Weights and the cylinder block,said weights each having a cam surface engaging a follower to increasethe pressure as the speed of rotation of the shaft increases.

Other objects will become readily apparent from the following detaileddescription taken in connection with the accompanying drawings in which:

Fig. 1 is a longitudinal section through a pump constructed inaccordance with the invention, taken along the line I-l of Fig. .2;

Fig. 2 is :a transverse section 'through .the

(Cl. 10S-158) 2 center of thecylinder block, looking tothe right in Fig.l, underlying parts being shown in broken linesyand Fig. 3 is afragmentary transverse sectio taken along the lines 3 3 of Fig. l.

While there in shown in the drawing and hereinafter describedin detail apreferred form of the invention, it is to be understood that theinvention is not limited to the particular form and arrangement shown. tkis contemplated that various changes may be made by'those skilled inthe art `without departing from the spirit and scope of the appendedclaims.

Referring now'to the drawings, the pump comprises a casing designated.generally at It and including a cup-shaped body having side walls I l,a base I2 and a cover member I3 which may be secured on'the cup-shapedbody by a plurality of bolts I4.

Within the casing Hl is a chamber l5 having a cylindrical wall 15a andhaving an end wall 15b formed by the inner surface of the cover membert3. This end wall has an inner recess I6 which communicates by means ofa passage l'l with an outlet port 'i8 in the cover of the casing. Anannular rib I9 having an inner surface IQa'which forms part `of said endwall lEb of the chamber 15,' lseparates the inner recess I6 from vaconcentric annular outer recess 2B. This outer recess communicates by4means of a passage 2| with 'an .inlet port 22 in the vcover member i3.

A .cylindrical cylinder block 25 is non-rotatably mounted within thechamber l5, the cylinder block having a smaller diameter than saidychamber. The cylinder block has one end face 25a engaging the end walllb so that the surface 19a of the annular rib YI9 may, by engagementwith the end face 25a, form a seal between the recesses 'I6 landAZl. Thecylinder block 25 has a central well 26 in its other end face which doesnot extend through the block, as shown in Fig. 1. The cylinder block 25has equally spaced around its periphery a plurality of cylinders 2M, 2lband 2'lc,which are preferably angular to radii of the block in order .toincrease the length of the cylinders. Each cylinder has near its innerend a port 23a, 28h and 28o respectively, which ports -open into the.end 'face A5a of the cylinder block. It iis :not lnecessary that theports open directly vinto the face of the cylinder block, .but the portsmay extend through channels defining an arc and opening into said endface 25a in positions to give properly timed valve a-ction, as willhereafter be described. Pistons 29a, "29h and 29e are mounted one ineach cylinder for reciprocation therein. Each piston has a portionextending out of the cylinder and engaging the cylindrical wall Ia ofthe chamber I5, as shown in Fig. 2. Springs 30a, 38h and 30C areprovided to urge the pistons "outwardly, although these springs are notnecessary if the pump intake is under pressure.

A drive shaft 3i is rotatably mounted in sleeve bearings 32 and 33 inthe casing I0, and the inner end of the shaft has an eccentricprojection 3Ia forming a crank which fits movably in the well 26 of thecylinder block 25, a bushing 34 providing a rotatable mounting for thecrank in the well. A flexible sleeve 35 connects the block 25 with theend wall I2 of the casing. This sleeve is connected at one end to thecylinder block by clamping bolts 36, a clamping ring 31 and a gasket 38.The other end of the sleeve is connected to the casing by means ofclamping bolts 39 which extend through the casing base I2, a clampingring 40, and a gasket 4I. The flexible sleeve 35 surrounds the shaft 3Iand provides a non-rotatable seal between the cylinder ports and theshaft, and consequently no rotary seal is required for the shaft 3|. Adrain 42 is provided between the chamber I5 and the inlet 22.

A spider is pinned to the drive shaft 3| and a pair of oppositelydisposed weights 46a and 4Gb are pivotally mounted on the spider, theseweights each having a cam surface 46a and 4Gb for engagement with anannular follower 4I forming part of a thrust bearing having an annularmember 48 secured to the cylinder block 25. In the space between themembers 4'! and 48 is a ball retainer 49 carrying a plurality ofanti-friction balls 50.

In the operation of the pump, the drive shaft is rotated and theeccentric crank 3 la causes the cylinder block 25 to move bodily in agenerally circular path in the chamber I5. The block is held againstrotation by the sleeve 35, although the exibility of the sleeve permitsarcuate movement of the block about its axis when necessary. As theblock moves bodily within the chamber I5, the pistons 29 arereciprocated successively through compression and suction strokes andthe respective ports 28 are moved across the surface I9a of the annularrib I9 alternately into communication with the recesses I6 and 20. Aspointed out above, the positions at which the respective cylinder ports28 open into the end face 25a provides proper valving action incorrectly timed relationship with the reciprocal movement of thepistons.

Obviously, in order to create a pumping action the recesses I6 and 20must be sealed one from the other, for if no seal exists no pressure inexcess of the inlet pressure can be developed in the outlet, but thefluid being pumped will merely flow back to the inlet on the compressionstroke of each piston. As the drive shaft 3l is rotated, the weights 46act as a iiyball governor device and move outwardly away from the shaft3I in an amount dependent upon the speed of rotation of said shaft. Asthese weights move outwardly, they cam the thrust bearing device to theright (as the parts appear in Fig. 1) to exert pressure against thecylinder block 25, this pressure varying as a function of speed ofrotation of the shaft and increasing as the speed of rotation of theshaft increases.

I prefer to arrange the parts so that the force exerted by the flyballgovernor will create a seal sufficient to balance the pressure desiredto be developed in the outlet recess I8 at a speed of rotation which isslightly below the operating speed of the pump. For example, in a pumpdeveloping pounds per square inch pressure in the pressure chamber onthe outlet side, the governor weights are so Constructed and arrangedthat the force developed by the governor will create a seal sufficientto balance 100 pounds pressure in the recess I6 at a speed of 1700 R. P.M. of the drive shaft. During operation, the shaft rotates at 1800 R. P.M. Consequently, pumping pressure will not be developed ,until the pumpreaches nearly top speed. When the drive shaft is stationary, the forceexerted by the governor is zero, and there is no seal, so that thestarting torque of the device will be at a minimum. The motor will,therefore, accelerate rapidly until a speed of 1700 R. P. M. is reachedat which point the pump will be at effective operating condition and bedeveloping 100 p. s. i. pressure, and at 1800 R. P. M. the pressure ofthe fiyball governor device will create an effective seal between therecesses I6 and 28 to maintain this pressure with little or no loss.When the pump motor is shut olf, the pressure on the outlet side will bedissipated when the speed drops below 1700 R. P. M., reducing the torqueload so that the motor and pump are not rapidly braked, but may coast toa stop.

The provision of means for exerting variable pressure to force the endface of the block 25 against the end wall of the chamber I5 so that thepressure increases as the speed of movement of the block increases isconsiderably advantageous over means which provide a constant pressure,as for example a spring bearing against the block. With such a spring'the pump must start against the torque provided by full pumping action.

I claim:

.1.. A pump comprising in combination, a casing having a cylindricalchamber therein, means providing an end wall in the chamber having aninner recess and a concentric outer annular recess, an annular ribforming part of said wall and located intermediate the recesses toseparate the same, an inlet and an outlet port in the casing;passageways connecting said recesses respectively with the inlet andoutlet ports; a cylindrical cylinder block of smaller diameter than saidchamber nonrotatably mounted therein, a face at each end of the blockwith one end face engaging said end wall and with the other end facehaving a central well therein extending only partially through saidblock, a plurality of cylinders formed in the periphery of the block; acylinder port for each cylinder and opening into said end face; a pistonreciprocably mounted in each cylinder and having a portion extendingtherefrom and engaging the cylindrical lwall of said chamber; a driveshaft mounted in said casing for rotation about an axis normal to theplane of the first mentioned end face; an eccentric projection on theend of said shaft and fitting movably in the well in said block formoving said block bodily in a generally circular path upon rotation ofSaid shaft to reciprocate said pistons and to move said cylinder portsalternately into communication with said recesses; a flexible sleeveconnecting said block and casing and surrounding said shaft to provide anonrotatable seal between said cylinder ports and said shaft; and meansfor exerting variable pressure to force the first mentioned end face ofsaid block against the end wall of said chamber, lcomprising fa spideron 'saidfshaft a pair of o'ppos'itely disposed weights pivotally mountedon said `spider and movable awaylfromz-said spider as-'a function lofthe speed of "rotation of said fshalft, a thrust bearing between saidweights and block, and 1a cam Ssurface on .each weight and engaging thebearing to increase said pressure as the speed of rotation of :saidshaft increases.

f2.' .A pump compr'isingin combination,a casing havinga cylindricalchamber therein-means providing an end wall-inthe chamber having aninner recess and arconcentr-ic outer annular recess, .an annular rib'formingpart of saidvwall and .located intermediate the recessesto-'separate the same, an inlet and an `outlet in the casing;passageways connecting said recesses respectively with the inlet andoutlet ports; a cylindrical cylinder block of smaller diameter than saidchamber nonrotatably mounted therein, a face at each end of the blockwith one end face engaging said end wall and with the other end facehaving a central well therein extending only partially through saidblock, a plurality of cylinders formed in the periphery of the block; acylinder port for -each cylinder opening into said end face; a pistonreciprocably mounted in each cylinder and having a portion extendingtherefrom and engaging the cylindrical wall of said chamber; a driveshaft mounted in said casing for rotation about an'axis normal to theplane of the rst mentioned end face; an eccentric projection on the endof said shaft and fitting movably in the well in said block for movingsaid block bodily in a generally circular path upon rotation of saidshaft to reciprocate said pistons and to move said cylinder portsalternately into communication with said recesses; and means forexerting variable pressure to force the first mentioned end face of saidblock against the end wall of said chamber, said pressure increasing asthe speed of rotation of said shaft increases.

3. A pump comprising in combination, a casing having a cylindricalchamber therein, means providing and end wall in the chamber having aninner recess and a concentric outer annular recess, an annular ribforming part of said wall and located intermediate the recesses toseparate the same, an inlet and an outlet port in the casing; meansconnecting said recesses respectively with the inlet and outlet ports; acylindrical cylinder block of smaller diameter than said chambernonrotatably mounted therein, a face at each end of the block with oneend face engaging said end wall and said block having a plurality ofcylinders in its periphery each with a cylinder port opening into saidend face; a piston reciprocably mounted in each cylinder and having aportion extending therefrom and engaging the cylindrical Wall of saidchamber; a drive shaft mounted in said casing for rotation about an axisnormal to the plane of said end face; crank means movably coupling saidshaft to the other end face of said block for moving said block bodilyin a generally circular path upon rotation of said shaft to reciprocatesaid pistons and to move said cylinder ports alternately intocommunication with said recesses; a flexible sleeve connecting saidblock and casing and surrounding said shaft to provide a nonrotatableseal between said cylinder ports and said shaft; and means for exertingvariable pressure to force the rst mentioned end face of said blockagainst the end wall of said chamber, said last named means comprising afiyball governor device on said shaft and a v'thrust `bearing betweensaid governor and said other end face of the block, a follower connectedto the bearing and a cam surface on the governor engaging the fol--lower to increase the pressure on said bearing as the speedofrotation-ofsaid shaft increases.

4. -A pump comprising vin combination, -a casing having a cylindricallchamber vtherein, means defining an-end wall in the chamber vhav-inginlet and outlet openings; a Ycylindrical cylinder .block of smallerdiameter than .said chamber nonro'tatably mounted therein, a face ateach end of the block with one end face vengaging said end wall, acylinder in the lblock provided with Ya cylinder port Aopening into saidv'end face; :a piston reciprocably mounted in said cylinder and having aportion engageable with 'the cylindrical wall of said chamber; a driveshaft mounted lin said casing for rotation about an axis normal to theplane of the first mentioned end face; crank means movably coupling saidshaft to the other end face of said block for moving said block bodilyin a generally circular path upon rotation of said shaft to reciprocatesaid piston and to move said port alternately into communication withsaid openings; and means for exerting variable pressure to force thefirst mentioned end face of said block against the end wall of saidchamber, comprising a spider on said shaft, a pair of weights pivotallymounted on said spider and movable as a function of the speed ofrotation offsaid shaft, and a thrust bearing between said Weights andblock, a cam surface on the weights and engaging the bearing to increasesaid pressure as the speed of rotation of said shaft increases.

5. A pump comprising in combination, a casing having a cylindricalchamber therein, means defining an end Wall in the chamber having inletand outlet openings; a cylindrical cylinder block of smaller diameterthan said chamber nonrotatably mounted therein, a face at each end ofthe block with one end face engaging said end wall, a cylinder in theblock provided with a cylinder port opening into said end face; a pistonreciprocably mounted in said cylinder and having a portion engageablewith the cylindrical wall of said chamber; a drive shaft mounted in saidcasing for rotation about an axis normal to the plane of the firstmentioned end face; crank means movably coupling said shaft to the otherend face of said block forrmoving said block bodily in a generallycircular path upon rotation of said shaft to reciprocate said piston andto move said port alternately into communication with said openings; andmeans for exerting variable pressure to force the rst mentioned end faceof said block against the end wall of said chamber, comprising a flyballgovernor device on said shaft and a thrust bearing between said governorand said other end face of the block, and a cam surface operated by thegovernor to increase the pressure on said bearing as the speed ofrotation of said shaft increases.

6. A pump comprising in combination, a casing having a cylindricalchamber therein, means defining an end wall in the chamber having inletand outlet openings; a cylindrical cylinder block of smaller diameterthan said chamber nonrotatably mounted therein, a face at each end ofthe block with one end face engaging said end wall, a cylinder in theblock provided with a cylinder port opening into said end face; a pistonreciprocably mounted in said cylinder and having a portion engageablewith the cylindrical wall of said chamber; a drive shaft mounted in saidcasing for rotation about an aXis normal to the plane of the firstmentioned end face; crank means movably coupling said shaft to the otherend face of said block for moving said block 5 bodily in a generallycircular path upon rotation of said shaft to reciprocate said piston andto movesaid port alternately into communication withsaid openings; andmeans for exerting variable pressure to force the first mentioned end 10face of said block against the end Wall of said chamber, said pressureincreasing as the speed of rotation of said shaft increases.

7. A pump comprising in combination, a casing having a cylindricalchamber therein, means defining an end Wall in the chamber having inletand outlet openings; a cylindrical cylinder block of smaller diameterthan said chamber nonrotatably mounted therein, a face at each end ofthe block with one end face engaging said end wall, a cylinder in theblock provided with a cylinder` port opening into said end face; apiston reciprocably mounted in said cylinder and having a portionengageable With the cylindrical Wall of said chamber; means for movingsaid block bodily in a generally circular path with said portion of thepiston engaging the Wall of the chamber to reciprocate the piston in thecylinder and to bring said port alternately in communication With theinlet and outlet; and means for exerting variable pressure to force theend face of said block against the end Wall of said chamber, saidpressure increasing as the speed of said 15 movement increases.

FLOYD E. CARLSON.

No references cited.

